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How to handle the PROBLEM message? PROBLEM means anything except an action that requires a beam dump, i.e. is interlocked. or PROBLEM Proposal: LHC expects the message PROBLEM as an alternative to PREPARE or READY. Outside these three phases INJECTION, ADJUST and DUMP  Machine doesn’t use Handshake protocol and therefore the Machine doesn’t listen to msg PROBLEM. Other mechanism needed. Suggestion?  telephone. 10/08/20095R. Alemany - BE/OP/LHC

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How to communicate that the LHC synchronization phase is done and experiments can switch to LHC timing? Proposal: – Change beam mode to INJECTION PROBE BEAM – Check that the RF power is on – Prepare the RF Beam Control for filling (here we do all the synchronization) – Send the Handshake DIP message to experiments IMMINENT – Etc…. (the sequence goes on with other tasks) The beam mode change to INJECTION PROBE BEAM signals the start of the synchronization, the DIP message IMMINENT signals that the synchronization has been done successfully. 10/08/20096R. Alemany - BE/OP/LHC